The previous patch introduced a flag that specified pages in a VMA should
be placed on the unevictable LRU, but they should not be made present when
the area is created.  This patch adds the ability to set this state via
the new mlock system calls.

We add MLOCK_ONFAULT for mlock2 and MCL_ONFAULT for mlockall.
MLOCK_ONFAULT will set the VM_LOCKONFAULT modifier for VM_LOCKED.
MCL_ONFAULT should be used as a modifier to the two other mlockall flags.
When used with MCL_CURRENT, all current mappings will be marked with
VM_LOCKED | VM_LOCKONFAULT.  When used with MCL_FUTURE, the mm->def_flags
will be marked with VM_LOCKED | VM_LOCKONFAULT.  When used with both
MCL_CURRENT and MCL_FUTURE, all current mappings and mm->def_flags will be
marked with VM_LOCKED | VM_LOCKONFAULT.

Prior to this patch, mlockall() will unconditionally clear the
mm->def_flags any time it is called without MCL_FUTURE.  This behavior is
maintained after adding MCL_ONFAULT.  If a call to mlockall(MCL_FUTURE) is
followed by mlockall(MCL_CURRENT), the mm->def_flags will be cleared and
new VMAs will be unlocked.  This remains true with or without MCL_ONFAULT
in either mlockall() invocation.

munlock() will unconditionally clear both vma flags.  munlockall()
unconditionally clears for VMA flags on all VMAs and in the mm->def_flags
field.
Signed-off-by: NEric B Munson <emunson@akamai.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the setup_nr_nodes(), we have already initialized
node_possible_map.  So it is safe to use for_each_node here.

There are many places in the kernel that use hardcoded 'for' loop with
nr_node_ids, because all other architectures have numa nodes populated
serially.  That should be reason we had maintained the same for
powerpc.

But, since sparse numa node ids possible on powerpc, we unnecessarily
allocate memory for non existent numa nodes.

For e.g., on a system with 0,1,16,17 as numa nodes nr_node_ids=18 and
we allocate memory for nodes 2-14.  This patch we allocate memory for
only existing numa nodes.

The patch is boot tested on a 4 node tuleta, confirming with printks
that it works as expected.
Signed-off-by: NRaghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Blanchard <anton@samba.org>
Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: Greg Kurz <gkurz@linux.vnet.ibm.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

probe_kernel_address() is basically the same as the (later added)
probe_kernel_read().

The return value on EFAULT is a bit different: probe_kernel_address()
returns number-of-bytes-not-copied whereas probe_kernel_read() returns
-EFAULT.  All callers have been checked, none cared.

probe_kernel_read() can be overridden by the architecture whereas
probe_kernel_address() cannot.  parisc, blackfin and um do this, to insert
additional checking.  Hence this patch possibly fixes obscure bugs,
although there are only two probe_kernel_address() callsites outside
arch/.

My first attempt involved removing probe_kernel_address() entirely and
converting all callsites to use probe_kernel_read() directly, but that got
tiresome.

This patch shrinks mm/slab_common.o by 218 bytes.  For a single
probe_kernel_address() callsite.

Cc: Steven Miao <realmz6@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When turning this from inline to an exported function I was a bit
over-eager and made it GPL only. This prevents the use of pretty much
all non-GPL PCI driver which is a bit over the top. Let's bring it
back in line with other architecture.

Fixes: 817820b0 ("powerpc/iommu: Support "hybrid" iommu/direct DMA ops for coherent_mask < dma_mask")
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Currently we do not validate rtas.entry before calling enter_rtas(). This
leads to a kernel oops when user space calls rtas system call on a powernv
platform (see below). This patch adds code to validate rtas.entry before
making enter_rtas() call.

  Oops: Exception in kernel mode, sig: 4 [#1]
  SMP NR_CPUS=1024 NUMA PowerNV
  task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000
  NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140
  REGS: c0000007e1a7b920 TRAP: 0e40   Not tainted  (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le)
  MSR: 1000000000081000 <HV,ME>  CR: 00000000  XER: 00000000
  CFAR: c000000000009c0c SOFTE: 0
  NIP [0000000000000000]           (null)
  LR [0000000000009c14] 0x9c14
  Call Trace:
  [c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable)
  [c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0
  [c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98

Cc: stable@vger.kernel.org # v3.2+
Fixes: 55190f88 ("powerpc: Add skeleton PowerNV platform")
Reported-by: NNAGESWARA R. SASTRY <nasastry@in.ibm.com>
Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Reword change log, trim oops, and add stable + fixes]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This fixes a bug where it is possible for an off-line CPU to fail to go
into a low-power state (nap/sleep/winkle), and to become unresponsive to
requests from the KVM subsystem to wake up and run a VCPU. What can
happen is that a maskable interrupt of some kind (external, decrementer,
hypervisor doorbell, or HMI) after we have called local_irq_disable() at
the beginning of pnv_smp_cpu_kill_self() and before interrupts are
hard-disabled inside power7_nap/sleep/winkle(). In this situation, the
pending event is marked in the irq_happened flag in the PACA. This
pending event prevents power7_nap/sleep/winkle from going to the
requested low-power state; instead they return immediately. We don't
deal with any of these pending event flags in the off-line loop in
pnv_smp_cpu_kill_self() because power7_nap et al. return 0 in this case,
so we will have srr1 == 0, and none of the processing to clear
interrupts or doorbells will be done.

Usually, the most obvious symptom of this is that a KVM guest will fail
with a console message saying "KVM: couldn't grab cpu N".

This fixes the problem by making sure we handle the irq_happened flags
properly. First, we hard-disable before the off-line loop. Once we have
hard-disabled, the irq_happened flags can't change underneath us. We
unconditionally clear the DEC and HMI flags: there is no processing of
timer interrupts while off-line, and the necessary HMI processing is all
done in lower-level code. We leave the EE and DBELL flags alone for the
first iteration of the loop, so that we won't fail to respond to a
split-core request that came in just before hard-disabling. Within the
loop, we handle external interrupts if the EE bit is set in irq_happened
as well as if the low-power state was interrupted by an external
interrupt. (We don't need to do the msgclr for a pending doorbell in
irq_happened, because doorbells are edge-triggered and don't remain
pending in hardware.) Then we clear both the EE and DBELL flags, and
once clear, they cannot be set again (until this CPU comes online again,
that is).

This also fixes the debug check to not be done when we just ran a KVM
guest or when the sleep didn't happen because of a pending event in
irq_happened.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This reverts commit 9678cdaa ("Use the POWER8 Micro Partition
Prefetch Engine in KVM HV on POWER8") because the original commit had
multiple, partly self-cancelling bugs, that could cause occasional
memory corruption.

In fact the logmpp instruction was incorrectly using register r0 as the
source of the buffer address and operation code, and depending on what
was in r0, it would either do nothing or corrupt the 64k page pointed to
by r0.

The logmpp instruction encoding and the operation code definitions could
be corrected, but then there is the problem that there is no clearly
defined way to know when the hardware has finished writing to the
buffer.

The original commit attempted to work around this by aborting the
write-out before starting the prefetch, but this is ineffective in the
case where the virtual core is now executing on a different physical
core from the one where the write-out was initiated.

These problems plus advice from the hardware designers not to use the
function (since the measured performance improvement from using the
feature was actually mostly negative), mean that reverting the code is
the best option.

Fixes: 9678cdaa ("Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8")
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The patch catches PERF_SAMPLE_BRANCH_CALL because it is not clear whether
this is actually supported by the hardware.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: khandual@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1444720151-10275-4-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The struct irq_domain contains a "struct device_node *" field
(of_node) that is almost the only link between the irqdomain
and the device tree infrastructure.

In order to prepare for the removal of that field, convert all
users to use irq_domain_get_of_node() instead.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-and-tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Graeme Gregory <graeme@xora.org.uk>
Cc: Jake Oshins <jakeo@microsoft.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Link: http://lkml.kernel.org/r/1444737105-31573-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

All unrecovered machine check errors on PowerNV should cause an
immediate panic. There are 2 reasons that this is the right policy:
it's not safe to continue, and we're already trying to reboot.

Firstly, if we go through the recovery process and do not successfully
recover, we can't be sure about the state of the machine, and it is
not safe to recover and proceed.

Linux knows about the following sources of Machine Check Errors:
- Uncorrectable Errors (UE)
- Effective - Real Address Translation (ERAT)
- Segment Lookaside Buffer (SLB)
- Translation Lookaside Buffer (TLB)
- Unknown/Unrecognised

In the SLB, TLB and ERAT cases, we can further categorise these as
parity errors, multihit errors or unknown/unrecognised.

We can handle SLB errors by flushing and reloading the SLB. We can
handle TLB and ERAT multihit errors by flushing the TLB. (It appears
we may not handle TLB and ERAT parity errors: I will investigate
further and send a followup patch if appropriate.)

This leaves us with uncorrectable errors. Uncorrectable errors are
usually the result of ECC memory detecting an error that it cannot
correct, but they also crop up in the context of PCI cards failing
during DMA writes, and during CAPI error events.

There are several types of UE, and there are 3 places a UE can occur:
Skiboot, the kernel, and userspace. For Skiboot errors, we have the
facility to make some recoverable. For userspace, we can simply kill
(SIGBUS) the affected process. We have no meaningful way to deal with
UEs in kernel space or in unrecoverable sections of Skiboot.

Currently, these unrecovered UEs fall through to
machine_check_expection() in traps.c, which calls die(), which OOPSes
and sends SIGBUS to the process. This sometimes allows us to stumble
onwards. For example we've seen UEs kill the kernel eehd and
khugepaged. However, the process killed could have held a lock, or it
could have been a more important process, etc: we can no longer make
any assertions about the state of the machine. Similarly if we see a
UE in skiboot (and again we've seen this happen), we're not in a
position where we can make any assertions about the state of the
machine.

Likewise, for unknown or unrecognised errors, we're not able to say
anything about the state of the machine.

Therefore, if we have an unrecovered MCE, the most appropriate thing
to do is to panic.

The second reason is that since e784b649 ("powerpc/powernv: Invoke
opal_cec_reboot2() on unrecoverable machine check errors."), we
attempt a special OPAL reboot on an unhandled MCE. This is so the
hardware can record error data for later debugging.

The comments in that commit assert that we are heading down the panic
path anyway. At the moment this is not always true. With UEs in kernel
space, for instance, they are marked as recoverable by the hardware,
so if the attempt to reboot failed (e.g. old Skiboot), we wouldn't
panic() but would simply die() and OOPS. It doesn't make sense to be
staggering on if we've just tried to reboot: we should panic().

Explicitly panic() on unrecovered MCEs on PowerNV.
Update the comments appropriately.

This fixes some hangs following EEH events on cxlflash setups.
Signed-off-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

native_hpte_clear() is called in real mode from two places:
- Early in boot during htab initialisation if firmware assisted dump is
  active.
- Late in the kexec path.

In both contexts there is no need to disable interrupts are they are
already disabled. Furthermore, locking around the tlbie() is only required
for pre POWER5 hardware.

On POWER5 or newer hardware concurrent tlbie()s work as expected and on pre
POWER5 hardware concurrent tlbie()s could result in deadlock. This code
would only be executed at crashdump time, during which all bets are off,
concurrent tlbie()s are unlikely and taking locks is unsafe therefore the
best course of action is to simply do nothing. Concurrent tlbie()s are not
possible in the first case as secondary CPUs have not come up yet.
Signed-off-by: NCyril Bur <cyrilbur@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

For some reason, only the little-endian flavor of
powerpc provided the zero_bytemask() implementation.
Reported-by: NMichal Sojka <sojkam1@fel.cvut.cz>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NChris Metcalf <cmetcalf@ezchip.com>

Enable the "wake-on-filer" (aka. wake on user defined packet)
wake on lan capability for the eTSEC ethernet nodes.

Cc: Li Yang <leoli@freescale.com>
Cc: Zhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: NClaudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/tile added word-at-a-time.h after the patch that added generic-y
entries; the generic-y entry is now stale.

arch/h8300 is newer than the generic-y patch for word-at-a-time.h,
and needs a generic-y entry.

arch/powerpc seems to have gotten a generic-y entry by mistake in
the first patch; this change removes it.
Signed-off-by: NChris Metcalf <cmetcalf@ezchip.com>

As we need to add further flags to the bpf_prog structure, lets migrate
both bools to a bitfield representation. The size of the base structure
(excluding insns) remains unchanged at 40 bytes.

Add also tags for the kmemchecker, so that it doesn't throw false
positives. Even in case gcc would generate suboptimal code, it's not
being accessed in performance critical paths.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This struct is unused, which is now a build error with gcc 6:

  error: 'os_area_db_id_video_mode' defined but not used

There doesn't seem to be any good reason to keep it around so remove it,
it's in the history if anyone needs it.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Commit 086b91d0 ("scsi_dh: integrate into the core SCSI code")
changed CONFIG_SCSI_DH from tristate to bool.

Our defconfigs have CONFIG_SCSI_DH=m, which the kconfig machinery warns
us is invalid, but instead of converting it to =y it leaves it unset.
This means we loose the CONFIG_SCSI_DH code and everything that depends
on it.

So convert the values in the defconfigs to =y.

Fixes: 086b91d0 ("scsi_dh: integrate into the core SCSI code")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

We observed some performance degradation on s390x with dynamic
halt polling. Until we can provide a proper fix, let's enable
halt_poll_ns as default only for supported architectures.

Architectures are now free to set their own halt_poll_ns
default value.
Signed-off-by: NDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The selftest passes on 64-bit LE & BE, and 32-bit.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Access to the kvm->buses (like with the kvm_io_bus_read() and -write()
functions) has to be protected via the kvm->srcu lock.
The kvmppc_h_logical_ci_load() and -store() functions are missing
this lock so far, so let's add it there, too.
This fixes the problem that the kernel reports "suspicious RCU usage"
when lock debugging is enabled.

Cc: stable@vger.kernel.org # v4.1+
Fixes: 99342cf8Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

In guest_exit_cont we call kvmhv_commence_exit which expects the trap
number as the argument. However r3 doesn't contain the trap number at
this point and as a result we would be calling the function with a
spurious trap number.

Fix this by copying r12 into r3 before calling kvmhv_commence_exit as
r12 contains the trap number.

Cc: stable@vger.kernel.org # v4.1+
Fixes: eddb60fbSigned-off-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This fixes a bug which results in stale vcore pointers being left in
the per-cpu preempted vcore lists when a VM is destroyed.  The result
of the stale vcore pointers is usually either a crash or a lockup
inside collect_piggybacks() when another VM is run.  A typical
lockup message looks like:

[  472.161074] NMI watchdog: BUG: soft lockup - CPU#24 stuck for 22s! [qemu-system-ppc:7039]
[  472.161204] Modules linked in: kvm_hv kvm_pr kvm xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw ses enclosure shpchp rtc_opal i2c_opal powernv_rng binfmt_misc dm_service_time scsi_dh_alua radeon i2c_algo_bit drm_kms_helper ttm drm tg3 ptp pps_core cxgb3 ipr i2c_core mdio dm_multipath [last unloaded: kvm_hv]
[  472.162111] CPU: 24 PID: 7039 Comm: qemu-system-ppc Not tainted 4.2.0-kvm+ #49
[  472.162187] task: c000001e38512750 ti: c000001e41bfc000 task.ti: c000001e41bfc000
[  472.162262] NIP: c00000000096b094 LR: c00000000096b08c CTR: c000000000111130
[  472.162337] REGS: c000001e41bff520 TRAP: 0901   Not tainted  (4.2.0-kvm+)
[  472.162399] MSR: 9000000100009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24848844  XER: 00000000
[  472.162588] CFAR: c00000000096b0ac SOFTE: 1
GPR00: c000000000111170 c000001e41bff7a0 c00000000127df00 0000000000000001
GPR04: 0000000000000003 0000000000000001 0000000000000000 0000000000874821
GPR08: c000001e41bff8e0 0000000000000001 0000000000000000 d00000000efde740
GPR12: c000000000111130 c00000000fdae400
[  472.163053] NIP [c00000000096b094] _raw_spin_lock_irqsave+0xa4/0x130
[  472.163117] LR [c00000000096b08c] _raw_spin_lock_irqsave+0x9c/0x130
[  472.163179] Call Trace:
[  472.163206] [c000001e41bff7a0] [c000001e41bff7f0] 0xc000001e41bff7f0 (unreliable)
[  472.163295] [c000001e41bff7e0] [c000000000111170] __wake_up+0x40/0x90
[  472.163375] [c000001e41bff830] [d00000000efd6fc0] kvmppc_run_core+0x1240/0x1950 [kvm_hv]
[  472.163465] [c000001e41bffa30] [d00000000efd8510] kvmppc_vcpu_run_hv+0x5a0/0xd90 [kvm_hv]
[  472.163559] [c000001e41bffb70] [d00000000e9318a4] kvmppc_vcpu_run+0x44/0x60 [kvm]
[  472.163653] [c000001e41bffba0] [d00000000e92e674] kvm_arch_vcpu_ioctl_run+0x64/0x170 [kvm]
[  472.163745] [c000001e41bffbe0] [d00000000e9263a8] kvm_vcpu_ioctl+0x538/0x7b0 [kvm]
[  472.163834] [c000001e41bffd40] [c0000000002d0f50] do_vfs_ioctl+0x480/0x7c0
[  472.163910] [c000001e41bffde0] [c0000000002d1364] SyS_ioctl+0xd4/0xf0
[  472.163986] [c000001e41bffe30] [c000000000009260] system_call+0x38/0xd0
[  472.164060] Instruction dump:
[  472.164098] ebc1fff0 ebe1fff8 7c0803a6 4e800020 60000000 60000000 60420000 8bad02e2
[  472.164224] 7fc3f378 4b6a57c1 60000000 7c210b78 <e92d0000> 89290009 792affe3 40820070

The bug is that kvmppc_run_vcpu does not correctly handle the case
where a vcpu task receives a signal while its guest vcpu is executing
in the guest as a result of being piggy-backed onto the execution of
another vcore.  In that case we need to wait for the vcpu to finish
executing inside the guest, and then remove this vcore from the
preempted vcores list.  That way, we avoid leaving this vcpu's vcore
on the preempted vcores list when the vcpu gets interrupted.

Fixes: ec257165Reported-by: NThomas Huth <thuth@redhat.com>
Tested-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

memset() uses instruction dcbz to speed up clearing by not wasting time
loading cache line with data that will be overwritten.
Some platform like mpc52xx do no have cache active at startup and
can therefore not use memset(). Allthough no part of the code
explicitly uses memset(), GCC may make calls to it.

This patch modifies memset() such that at startup, memset()
unconditionally skip the optimised bloc that uses dcbz instruction.

Once the initial MMU is set up, in machine_init() we patch memset()
by replacing this inconditional jump by a NOP
Tested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

memcpy() uses instruction dcbz to speed up copy by not wasting time
loading cache line with data that will be overwritten.
Some platform like mpc52xx do no have cache active at startup and
can therefore not use memcpy(). Allthough no part of the code
explicitly uses memcpy(), GCC makes calls to it.

This patch modifies memcpy() such that at startup, memcpy()
unconditionally jumps to generic_memcpy() which doesn't use
the dcbz instruction.

Once the initial MMU is set up, in machine_init() we patch memcpy()
by replacing this inconditional jump by a NOP
Reported-by: NMichal Sojka <sojkam1@fel.cvut.cz>
Tested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.

Remove the argument.

Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>

Use irq_set_handler_locked() as it avoids a redundant lookup of the
irq descriptor.

Search and replacement was done with coccinelle:

@@
struct irq_data *d;
expression E1;
@@

-__irq_set_handler_locked(d->irq, E1);
+irq_set_handler_locked(d, E1);
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org

Use irq_set_handler_locked() as it avoids a redundant lookup of the
irq descriptor.

Search and replacement was done with coccinelle:

@@
struct irq_data *d;
expression E1;
@@

-__irq_set_handler_locked(d->irq, E1);
+irq_set_handler_locked(d, E1);
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Blanchard <anton@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org

Use irq_set_handler_locked() as it avoids a redundant lookup of the
irq descriptor.

Search and replacement was done with coccinelle:

@@
struct irq_data *d;
expression E1;
@@

-__irq_set_handler_locked(d->irq, E1);
+irq_set_handler_locked(d, E1);
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org

Use irq_set_handler_locked() as it avoids a redundant lookup of the
irq descriptor.

Search and replacement was done with coccinelle:

@@
struct irq_data *d;
expression E1;
@@

-__irq_set_handler_locked(d->irq, E1);
+irq_set_handler_locked(d, E1);
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org

If we had secondary hash flag set, we ended up modifying hash value in
the updatepp code path. Hence with a failed updatepp we will be using
a wrong hash value for the following hash insert. Fix this by
recomputing hash before insert.

Without this patch we can end up with using wrong slot number in linux
pte. That can result in us missing an hash pte update or invalidate
which can cause memory corruption or even machine check.

Fixes: 6d492ecc ("powerpc/THP: Add code to handle HPTE faults for hugepages")
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The kernel does it, not the boot wrapper, which breaks with some
cross compilers that still default to ABI v1.

Fixes: 147c0516 ("powerpc/boot: Add support for 64bit little endian wrapper")
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This new statistic can help diagnosing VCPUs that, for any reason,
trigger bad behavior of halt_poll_ns autotuning.

For example, say halt_poll_ns = 480000, and wakeups are spaced exactly
like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes
10+20+40+80+160+320+480 = 1110 microseconds out of every
479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then
is consuming about 30% more CPU than it would use without
polling.  This would show as an abnormally high number of
attempted polling compared to the successful polls.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com<
Reviewed-by: NDavid Matlack <dmatlack@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Revert dff22d20 ("PCI: Call pci_read_bridge_bases() from core instead
of arch code").

Reading PCI bridge windows is not arch-specific in itself, but there is PCI
core code that doesn't work correctly if we read them too early.  For
example, Hannes found this case on an ARM Freescale i.mx6 board:

  pci_bus 0000:00: root bus resource [mem 0x01000000-0x01efffff]
  pci 0000:00:00.0: PCI bridge to [bus 01-ff]
  pci 0000:00:00.0: BAR 8: no space for [mem size 0x01000000] (mem window)
  pci 0000:01:00.0: BAR 2: failed to assign [mem size 0x00200000]
  pci 0000:01:00.0: BAR 1: failed to assign [mem size 0x00004000]
  pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x00000100]

The 00:00.0 mem window needs to be at least 3MB: the 01:00.0 device needs
0x204100 of space, and mem windows are megabyte-aligned.

Bus sizing can increase a bridge window size, but never *decrease* it (see
d65245c3 ("PCI: don't shrink bridge resources")).  Prior to
dff22d20, ARM didn't read bridge windows at all, so the "original size"
was zero, and we assigned a 3MB window.

After dff22d20, we read the bridge windows before sizing the bus.  The
firmware programmed a 16MB window (size 0x01000000) in 00:00.0, and since
we never decrease the size, we kept 16MB even though we only needed 3MB.
But 16MB doesn't fit in the host bridge aperture, so we failed to assign
space for the window and the downstream devices.

I think this is a defect in the PCI core: we shouldn't rely on the firmware
to assign sensible windows.

Ray reported a similar problem, also on ARM, with Broadcom iProc.

Issues like this are too hard to fix right now, so revert dff22d20.
Reported-by: NHannes <oe5hpm@gmail.com>
Reported-by: NRay Jui <rjui@broadcom.com>
Link: http://lkml.kernel.org/r/CAAa04yFQEUJm7Jj1qMT57-LG7ZGtnhNDBe=PpSRa70Mj+XhW-A@mail.gmail.com
Link: http://lkml.kernel.org/r/55F75BB8.4070405@broadcom.comSigned-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Use access helper irq_data_get_affinity_mask() so we can move the
affinity mask to irq_common_data.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1433145945-789-25-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.
    
Search and update was done with coccinelle and the invaluable help of
Julia Lawall.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org

The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.
    
Search and update was done with coccinelle and the invaluable help of
Julia Lawall.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: linuxppc-dev@lists.ozlabs.org

The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.
    
Search and update was done with coccinelle and the invaluable help of
Julia Lawall.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: linuxppc-dev@lists.ozlabs.org

We currently use PERF_EVENT_TXN flag to determine if we are in the middle
of a transaction. If in a transaction, we defer the schedulability checks
from pmu->add() operation to the pmu->commit() operation.

Now that we have "transaction types" (PERF_PMU_TXN_ADD, PERF_PMU_TXN_READ)
we can use the type to determine if we are in a transaction and drop the
PERF_EVENT_TXN flag.

When PERF_EVENT_TXN is dropped, the cpuhw->group_flag on some architectures
becomes unused, so drop that field as well.

This is an extension of the Powerpc patch from Peter Zijlstra to s390,
Sparc and x86 architectures.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-11-git-send-email-sukadev@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The 24x7 counters in Powerpc allow monitoring a large number of counters
simultaneously. They also allow reading several counters in a single
HCALL so we can get a more consistent snapshot of the system.

Use the PMU's transaction interface to monitor and read several event
counters at once. The idea is that users can group several 24x7 events
into a single group of events. We use the following logic to submit
the group of events to the PMU and read the values:

	pmu->start_txn()		// Initialize before first event

	for each event in group
		pmu->read(event);	// Queue each event to be read

	pmu->commit_txn()		// Read/update all queuedcounters

The ->commit_txn() also updates the event counts in the respective
perf_event objects.  The perf subsystem can then directly get the
event counts from the perf_event and can avoid submitting a new
->read() request to the PMU.

Thanks to input from Peter Zijlstra.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-10-git-send-email-sukadev@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently, the PMU interface allows reading only one counter at a time.
But some PMUs like the 24x7 counters in Power, support reading several
counters at once. To leveage this functionality, extend the transaction
interface to support a "transaction type".

The first type, PERF_PMU_TXN_ADD, refers to the existing transactions,
i.e. used to _schedule_ all the events on the PMU as a group. A second
transaction type, PERF_PMU_TXN_READ, will be used in a follow-on patch,
by the 24x7 counters to read several counters at once.

Extend the transaction interfaces to the PMU to accept a 'txn_flags'
parameter and use this parameter to ignore any transactions that are
not of type PERF_PMU_TXN_ADD.

Thanks to Peter Zijlstra for his input.
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[peterz: s390 compile fix]
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-3-git-send-email-sukadev@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>